1 /* $OpenBSD: sched_bsd.c,v 1.49 2019/01/28 11:48:13 mpi Exp $ */ 2 /* $NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $ */ 3 4 /*- 5 * Copyright (c) 1982, 1986, 1990, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * (c) UNIX System Laboratories, Inc. 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)kern_synch.c 8.6 (Berkeley) 1/21/94 38 */ 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/proc.h> 43 #include <sys/kernel.h> 44 #include <sys/malloc.h> 45 #include <sys/signalvar.h> 46 #include <sys/resourcevar.h> 47 #include <uvm/uvm_extern.h> 48 #include <sys/sched.h> 49 #include <sys/timeout.h> 50 51 #ifdef KTRACE 52 #include <sys/ktrace.h> 53 #endif 54 55 56 int lbolt; /* once a second sleep address */ 57 int rrticks_init; /* # of hardclock ticks per roundrobin() */ 58 59 #ifdef MULTIPROCESSOR 60 struct __mp_lock sched_lock; 61 #endif 62 63 void schedcpu(void *); 64 void updatepri(struct proc *); 65 66 void 67 scheduler_start(void) 68 { 69 static struct timeout schedcpu_to; 70 71 /* 72 * We avoid polluting the global namespace by keeping the scheduler 73 * timeouts static in this function. 74 * We setup the timeout here and kick schedcpu once to make it do 75 * its job. 76 */ 77 timeout_set(&schedcpu_to, schedcpu, &schedcpu_to); 78 79 rrticks_init = hz / 10; 80 schedcpu(&schedcpu_to); 81 } 82 83 /* 84 * Force switch among equal priority processes every 100ms. 85 */ 86 void 87 roundrobin(struct cpu_info *ci) 88 { 89 struct schedstate_percpu *spc = &ci->ci_schedstate; 90 91 spc->spc_rrticks = rrticks_init; 92 93 if (ci->ci_curproc != NULL) { 94 if (spc->spc_schedflags & SPCF_SEENRR) { 95 /* 96 * The process has already been through a roundrobin 97 * without switching and may be hogging the CPU. 98 * Indicate that the process should yield. 99 */ 100 atomic_setbits_int(&spc->spc_schedflags, 101 SPCF_SHOULDYIELD); 102 } else { 103 atomic_setbits_int(&spc->spc_schedflags, 104 SPCF_SEENRR); 105 } 106 } 107 108 if (spc->spc_nrun) 109 need_resched(ci); 110 } 111 112 /* 113 * Constants for digital decay and forget: 114 * 90% of (p_estcpu) usage in 5 * loadav time 115 * 95% of (p_pctcpu) usage in 60 seconds (load insensitive) 116 * Note that, as ps(1) mentions, this can let percentages 117 * total over 100% (I've seen 137.9% for 3 processes). 118 * 119 * Note that hardclock updates p_estcpu and p_cpticks independently. 120 * 121 * We wish to decay away 90% of p_estcpu in (5 * loadavg) seconds. 122 * That is, the system wants to compute a value of decay such 123 * that the following for loop: 124 * for (i = 0; i < (5 * loadavg); i++) 125 * p_estcpu *= decay; 126 * will compute 127 * p_estcpu *= 0.1; 128 * for all values of loadavg: 129 * 130 * Mathematically this loop can be expressed by saying: 131 * decay ** (5 * loadavg) ~= .1 132 * 133 * The system computes decay as: 134 * decay = (2 * loadavg) / (2 * loadavg + 1) 135 * 136 * We wish to prove that the system's computation of decay 137 * will always fulfill the equation: 138 * decay ** (5 * loadavg) ~= .1 139 * 140 * If we compute b as: 141 * b = 2 * loadavg 142 * then 143 * decay = b / (b + 1) 144 * 145 * We now need to prove two things: 146 * 1) Given factor ** (5 * loadavg) ~= .1, prove factor == b/(b+1) 147 * 2) Given b/(b+1) ** power ~= .1, prove power == (5 * loadavg) 148 * 149 * Facts: 150 * For x close to zero, exp(x) =~ 1 + x, since 151 * exp(x) = 0! + x**1/1! + x**2/2! + ... . 152 * therefore exp(-1/b) =~ 1 - (1/b) = (b-1)/b. 153 * For x close to zero, ln(1+x) =~ x, since 154 * ln(1+x) = x - x**2/2 + x**3/3 - ... -1 < x < 1 155 * therefore ln(b/(b+1)) = ln(1 - 1/(b+1)) =~ -1/(b+1). 156 * ln(.1) =~ -2.30 157 * 158 * Proof of (1): 159 * Solve (factor)**(power) =~ .1 given power (5*loadav): 160 * solving for factor, 161 * ln(factor) =~ (-2.30/5*loadav), or 162 * factor =~ exp(-1/((5/2.30)*loadav)) =~ exp(-1/(2*loadav)) = 163 * exp(-1/b) =~ (b-1)/b =~ b/(b+1). QED 164 * 165 * Proof of (2): 166 * Solve (factor)**(power) =~ .1 given factor == (b/(b+1)): 167 * solving for power, 168 * power*ln(b/(b+1)) =~ -2.30, or 169 * power =~ 2.3 * (b + 1) = 4.6*loadav + 2.3 =~ 5*loadav. QED 170 * 171 * Actual power values for the implemented algorithm are as follows: 172 * loadav: 1 2 3 4 173 * power: 5.68 10.32 14.94 19.55 174 */ 175 176 /* calculations for digital decay to forget 90% of usage in 5*loadav sec */ 177 #define loadfactor(loadav) (2 * (loadav)) 178 #define decay_cpu(loadfac, cpu) (((loadfac) * (cpu)) / ((loadfac) + FSCALE)) 179 180 /* decay 95% of `p_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */ 181 fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */ 182 183 /* 184 * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the 185 * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below 186 * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT). 187 * 188 * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used: 189 * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits). 190 * 191 * If you don't want to bother with the faster/more-accurate formula, you 192 * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate 193 * (more general) method of calculating the %age of CPU used by a process. 194 */ 195 #define CCPU_SHIFT 11 196 197 /* 198 * Recompute process priorities, every second. 199 */ 200 void 201 schedcpu(void *arg) 202 { 203 struct timeout *to = (struct timeout *)arg; 204 fixpt_t loadfac = loadfactor(averunnable.ldavg[0]); 205 struct proc *p; 206 int s; 207 unsigned int newcpu; 208 int phz; 209 210 /* 211 * If we have a statistics clock, use that to calculate CPU 212 * time, otherwise revert to using the profiling clock (which, 213 * in turn, defaults to hz if there is no separate profiling 214 * clock available) 215 */ 216 phz = stathz ? stathz : profhz; 217 KASSERT(phz); 218 219 LIST_FOREACH(p, &allproc, p_list) { 220 /* 221 * Idle threads are never placed on the runqueue, 222 * therefore computing their priority is pointless. 223 */ 224 if (p->p_cpu != NULL && 225 p->p_cpu->ci_schedstate.spc_idleproc == p) 226 continue; 227 /* 228 * Increment sleep time (if sleeping). We ignore overflow. 229 */ 230 if (p->p_stat == SSLEEP || p->p_stat == SSTOP) 231 p->p_slptime++; 232 p->p_pctcpu = (p->p_pctcpu * ccpu) >> FSHIFT; 233 /* 234 * If the process has slept the entire second, 235 * stop recalculating its priority until it wakes up. 236 */ 237 if (p->p_slptime > 1) 238 continue; 239 SCHED_LOCK(s); 240 /* 241 * p_pctcpu is only for diagnostic tools such as ps. 242 */ 243 #if (FSHIFT >= CCPU_SHIFT) 244 p->p_pctcpu += (phz == 100)? 245 ((fixpt_t) p->p_cpticks) << (FSHIFT - CCPU_SHIFT): 246 100 * (((fixpt_t) p->p_cpticks) 247 << (FSHIFT - CCPU_SHIFT)) / phz; 248 #else 249 p->p_pctcpu += ((FSCALE - ccpu) * 250 (p->p_cpticks * FSCALE / phz)) >> FSHIFT; 251 #endif 252 p->p_cpticks = 0; 253 newcpu = (u_int) decay_cpu(loadfac, p->p_estcpu); 254 p->p_estcpu = newcpu; 255 resetpriority(p); 256 if (p->p_priority >= PUSER) { 257 if (p->p_stat == SRUN && 258 (p->p_priority / SCHED_PPQ) != 259 (p->p_usrpri / SCHED_PPQ)) { 260 remrunqueue(p); 261 p->p_priority = p->p_usrpri; 262 setrunqueue(p); 263 } else 264 p->p_priority = p->p_usrpri; 265 } 266 SCHED_UNLOCK(s); 267 } 268 uvm_meter(); 269 wakeup(&lbolt); 270 timeout_add_sec(to, 1); 271 } 272 273 /* 274 * Recalculate the priority of a process after it has slept for a while. 275 * For all load averages >= 1 and max p_estcpu of 255, sleeping for at 276 * least six times the loadfactor will decay p_estcpu to zero. 277 */ 278 void 279 updatepri(struct proc *p) 280 { 281 unsigned int newcpu = p->p_estcpu; 282 fixpt_t loadfac = loadfactor(averunnable.ldavg[0]); 283 284 SCHED_ASSERT_LOCKED(); 285 286 if (p->p_slptime > 5 * loadfac) 287 p->p_estcpu = 0; 288 else { 289 p->p_slptime--; /* the first time was done in schedcpu */ 290 while (newcpu && --p->p_slptime) 291 newcpu = (int) decay_cpu(loadfac, newcpu); 292 p->p_estcpu = newcpu; 293 } 294 resetpriority(p); 295 } 296 297 /* 298 * General yield call. Puts the current process back on its run queue and 299 * performs a voluntary context switch. 300 */ 301 void 302 yield(void) 303 { 304 struct proc *p = curproc; 305 int s; 306 307 NET_ASSERT_UNLOCKED(); 308 309 SCHED_LOCK(s); 310 p->p_priority = p->p_usrpri; 311 p->p_stat = SRUN; 312 setrunqueue(p); 313 p->p_ru.ru_nvcsw++; 314 mi_switch(); 315 SCHED_UNLOCK(s); 316 } 317 318 /* 319 * General preemption call. Puts the current process back on its run queue 320 * and performs an involuntary context switch. If a process is supplied, 321 * we switch to that process. Otherwise, we use the normal process selection 322 * criteria. 323 */ 324 void 325 preempt(void) 326 { 327 struct proc *p = curproc; 328 int s; 329 330 SCHED_LOCK(s); 331 p->p_priority = p->p_usrpri; 332 p->p_stat = SRUN; 333 setrunqueue(p); 334 p->p_ru.ru_nivcsw++; 335 mi_switch(); 336 SCHED_UNLOCK(s); 337 } 338 339 void 340 mi_switch(void) 341 { 342 struct schedstate_percpu *spc = &curcpu()->ci_schedstate; 343 struct proc *p = curproc; 344 struct proc *nextproc; 345 struct process *pr = p->p_p; 346 struct timespec ts; 347 #ifdef MULTIPROCESSOR 348 int hold_count; 349 int sched_count; 350 #endif 351 352 assertwaitok(); 353 KASSERT(p->p_stat != SONPROC); 354 355 SCHED_ASSERT_LOCKED(); 356 357 #ifdef MULTIPROCESSOR 358 /* 359 * Release the kernel_lock, as we are about to yield the CPU. 360 */ 361 sched_count = __mp_release_all_but_one(&sched_lock); 362 if (_kernel_lock_held()) 363 hold_count = __mp_release_all(&kernel_lock); 364 else 365 hold_count = 0; 366 #endif 367 368 /* 369 * Compute the amount of time during which the current 370 * process was running, and add that to its total so far. 371 */ 372 nanouptime(&ts); 373 if (timespeccmp(&ts, &spc->spc_runtime, <)) { 374 #if 0 375 printf("uptime is not monotonic! " 376 "ts=%lld.%09lu, runtime=%lld.%09lu\n", 377 (long long)tv.tv_sec, tv.tv_nsec, 378 (long long)spc->spc_runtime.tv_sec, 379 spc->spc_runtime.tv_nsec); 380 #endif 381 } else { 382 timespecsub(&ts, &spc->spc_runtime, &ts); 383 timespecadd(&p->p_rtime, &ts, &p->p_rtime); 384 } 385 386 /* add the time counts for this thread to the process's total */ 387 tuagg_unlocked(pr, p); 388 389 /* 390 * Process is about to yield the CPU; clear the appropriate 391 * scheduling flags. 392 */ 393 atomic_clearbits_int(&spc->spc_schedflags, SPCF_SWITCHCLEAR); 394 395 nextproc = sched_chooseproc(); 396 397 if (p != nextproc) { 398 uvmexp.swtch++; 399 cpu_switchto(p, nextproc); 400 } else { 401 p->p_stat = SONPROC; 402 } 403 404 clear_resched(curcpu()); 405 406 SCHED_ASSERT_LOCKED(); 407 408 /* 409 * To preserve lock ordering, we need to release the sched lock 410 * and grab it after we grab the big lock. 411 * In the future, when the sched lock isn't recursive, we'll 412 * just release it here. 413 */ 414 #ifdef MULTIPROCESSOR 415 __mp_unlock(&sched_lock); 416 #endif 417 418 SCHED_ASSERT_UNLOCKED(); 419 420 /* 421 * We're running again; record our new start time. We might 422 * be running on a new CPU now, so don't use the cache'd 423 * schedstate_percpu pointer. 424 */ 425 KASSERT(p->p_cpu == curcpu()); 426 427 nanouptime(&p->p_cpu->ci_schedstate.spc_runtime); 428 429 #ifdef MULTIPROCESSOR 430 /* 431 * Reacquire the kernel_lock now. We do this after we've 432 * released the scheduler lock to avoid deadlock, and before 433 * we reacquire the interlock and the scheduler lock. 434 */ 435 if (hold_count) 436 __mp_acquire_count(&kernel_lock, hold_count); 437 __mp_acquire_count(&sched_lock, sched_count + 1); 438 #endif 439 } 440 441 static __inline void 442 resched_proc(struct proc *p, u_char pri) 443 { 444 struct cpu_info *ci; 445 446 /* 447 * XXXSMP 448 * This does not handle the case where its last 449 * CPU is running a higher-priority process, but every 450 * other CPU is running a lower-priority process. There 451 * are ways to handle this situation, but they're not 452 * currently very pretty, and we also need to weigh the 453 * cost of moving a process from one CPU to another. 454 * 455 * XXXSMP 456 * There is also the issue of locking the other CPU's 457 * sched state, which we currently do not do. 458 */ 459 ci = (p->p_cpu != NULL) ? p->p_cpu : curcpu(); 460 if (pri < ci->ci_schedstate.spc_curpriority) 461 need_resched(ci); 462 } 463 464 /* 465 * Change process state to be runnable, 466 * placing it on the run queue if it is in memory, 467 * and awakening the swapper if it isn't in memory. 468 */ 469 void 470 setrunnable(struct proc *p) 471 { 472 SCHED_ASSERT_LOCKED(); 473 474 switch (p->p_stat) { 475 case 0: 476 case SRUN: 477 case SONPROC: 478 case SDEAD: 479 case SIDL: 480 default: 481 panic("setrunnable"); 482 case SSTOP: 483 /* 484 * If we're being traced (possibly because someone attached us 485 * while we were stopped), check for a signal from the debugger. 486 */ 487 if ((p->p_p->ps_flags & PS_TRACED) != 0 && p->p_xstat != 0) 488 atomic_setbits_int(&p->p_siglist, sigmask(p->p_xstat)); 489 case SSLEEP: 490 unsleep(p); /* e.g. when sending signals */ 491 break; 492 } 493 p->p_stat = SRUN; 494 p->p_cpu = sched_choosecpu(p); 495 setrunqueue(p); 496 if (p->p_slptime > 1) 497 updatepri(p); 498 p->p_slptime = 0; 499 resched_proc(p, p->p_priority); 500 } 501 502 /* 503 * Compute the priority of a process when running in user mode. 504 * Arrange to reschedule if the resulting priority is better 505 * than that of the current process. 506 */ 507 void 508 resetpriority(struct proc *p) 509 { 510 unsigned int newpriority; 511 512 SCHED_ASSERT_LOCKED(); 513 514 newpriority = PUSER + p->p_estcpu + 515 NICE_WEIGHT * (p->p_p->ps_nice - NZERO); 516 newpriority = min(newpriority, MAXPRI); 517 p->p_usrpri = newpriority; 518 resched_proc(p, p->p_usrpri); 519 } 520 521 /* 522 * We adjust the priority of the current process. The priority of a process 523 * gets worse as it accumulates CPU time. The cpu usage estimator (p_estcpu) 524 * is increased here. The formula for computing priorities (in kern_synch.c) 525 * will compute a different value each time p_estcpu increases. This can 526 * cause a switch, but unless the priority crosses a PPQ boundary the actual 527 * queue will not change. The cpu usage estimator ramps up quite quickly 528 * when the process is running (linearly), and decays away exponentially, at 529 * a rate which is proportionally slower when the system is busy. The basic 530 * principle is that the system will 90% forget that the process used a lot 531 * of CPU time in 5 * loadav seconds. This causes the system to favor 532 * processes which haven't run much recently, and to round-robin among other 533 * processes. 534 */ 535 void 536 schedclock(struct proc *p) 537 { 538 struct cpu_info *ci = curcpu(); 539 struct schedstate_percpu *spc = &ci->ci_schedstate; 540 int s; 541 542 if (p == spc->spc_idleproc) 543 return; 544 545 SCHED_LOCK(s); 546 p->p_estcpu = ESTCPULIM(p->p_estcpu + 1); 547 resetpriority(p); 548 if (p->p_priority >= PUSER) 549 p->p_priority = p->p_usrpri; 550 SCHED_UNLOCK(s); 551 } 552 553 void (*cpu_setperf)(int); 554 555 #define PERFPOL_MANUAL 0 556 #define PERFPOL_AUTO 1 557 #define PERFPOL_HIGH 2 558 int perflevel = 100; 559 int perfpolicy = PERFPOL_MANUAL; 560 561 #ifndef SMALL_KERNEL 562 /* 563 * The code below handles CPU throttling. 564 */ 565 #include <sys/sysctl.h> 566 567 void setperf_auto(void *); 568 struct timeout setperf_to = TIMEOUT_INITIALIZER(setperf_auto, NULL); 569 570 void 571 setperf_auto(void *v) 572 { 573 static uint64_t *idleticks, *totalticks; 574 static int downbeats; 575 576 int i, j; 577 int speedup; 578 CPU_INFO_ITERATOR cii; 579 struct cpu_info *ci; 580 uint64_t idle, total, allidle, alltotal; 581 582 if (perfpolicy != PERFPOL_AUTO) 583 return; 584 585 if (!idleticks) 586 if (!(idleticks = mallocarray(ncpusfound, sizeof(*idleticks), 587 M_DEVBUF, M_NOWAIT | M_ZERO))) 588 return; 589 if (!totalticks) 590 if (!(totalticks = mallocarray(ncpusfound, sizeof(*totalticks), 591 M_DEVBUF, M_NOWAIT | M_ZERO))) { 592 free(idleticks, M_DEVBUF, 593 sizeof(*idleticks) * ncpusfound); 594 return; 595 } 596 597 alltotal = allidle = 0; 598 j = 0; 599 speedup = 0; 600 CPU_INFO_FOREACH(cii, ci) { 601 total = 0; 602 for (i = 0; i < CPUSTATES; i++) { 603 total += ci->ci_schedstate.spc_cp_time[i]; 604 } 605 total -= totalticks[j]; 606 idle = ci->ci_schedstate.spc_cp_time[CP_IDLE] - idleticks[j]; 607 if (idle < total / 3) 608 speedup = 1; 609 alltotal += total; 610 allidle += idle; 611 idleticks[j] += idle; 612 totalticks[j] += total; 613 j++; 614 } 615 if (allidle < alltotal / 2) 616 speedup = 1; 617 if (speedup) 618 downbeats = 5; 619 620 if (speedup && perflevel != 100) { 621 perflevel = 100; 622 cpu_setperf(perflevel); 623 } else if (!speedup && perflevel != 0 && --downbeats <= 0) { 624 perflevel = 0; 625 cpu_setperf(perflevel); 626 } 627 628 timeout_add_msec(&setperf_to, 100); 629 } 630 631 int 632 sysctl_hwsetperf(void *oldp, size_t *oldlenp, void *newp, size_t newlen) 633 { 634 int err, newperf; 635 636 if (!cpu_setperf) 637 return EOPNOTSUPP; 638 639 if (perfpolicy != PERFPOL_MANUAL) 640 return sysctl_rdint(oldp, oldlenp, newp, perflevel); 641 642 newperf = perflevel; 643 err = sysctl_int(oldp, oldlenp, newp, newlen, &newperf); 644 if (err) 645 return err; 646 if (newperf > 100) 647 newperf = 100; 648 if (newperf < 0) 649 newperf = 0; 650 perflevel = newperf; 651 cpu_setperf(perflevel); 652 653 return 0; 654 } 655 656 int 657 sysctl_hwperfpolicy(void *oldp, size_t *oldlenp, void *newp, size_t newlen) 658 { 659 char policy[32]; 660 int err; 661 662 if (!cpu_setperf) 663 return EOPNOTSUPP; 664 665 switch (perfpolicy) { 666 case PERFPOL_MANUAL: 667 strlcpy(policy, "manual", sizeof(policy)); 668 break; 669 case PERFPOL_AUTO: 670 strlcpy(policy, "auto", sizeof(policy)); 671 break; 672 case PERFPOL_HIGH: 673 strlcpy(policy, "high", sizeof(policy)); 674 break; 675 default: 676 strlcpy(policy, "unknown", sizeof(policy)); 677 break; 678 } 679 680 if (newp == NULL) 681 return sysctl_rdstring(oldp, oldlenp, newp, policy); 682 683 err = sysctl_string(oldp, oldlenp, newp, newlen, policy, sizeof(policy)); 684 if (err) 685 return err; 686 if (strcmp(policy, "manual") == 0) 687 perfpolicy = PERFPOL_MANUAL; 688 else if (strcmp(policy, "auto") == 0) 689 perfpolicy = PERFPOL_AUTO; 690 else if (strcmp(policy, "high") == 0) 691 perfpolicy = PERFPOL_HIGH; 692 else 693 return EINVAL; 694 695 if (perfpolicy == PERFPOL_AUTO) { 696 timeout_add_msec(&setperf_to, 200); 697 } else if (perfpolicy == PERFPOL_HIGH) { 698 perflevel = 100; 699 cpu_setperf(perflevel); 700 } 701 return 0; 702 } 703 #endif 704